Using old cardboard boxes and packing tape, Caine constructed elaborate games, according to the film. He priced tickets — $1 for four plays or $2 for a “fun pass” and 500 plays.

He pinned prizes to the wall. He even developed a high-tech security system for validating the arcade fun passes.

Caine, wearing a blue staff t-shirt he made himself, waited for customers.

But didn’t get any. His dad’s shop in east L.A. does most of its business online and gets very little foot traffic.

Enter Nirvin Mullick, who needed a door handle for his 1996 Toyota Corolla. He explains in the film how he bought a fun pass (it was the better deal) and played some games.

It turns out that one customer was all Caine needed.

Mr. Mullick is a filmmaker and decided to make a video about Caine’s Arcade.

“I said (to Mr. Mullick), it’s actually kind of a little joke around here because you’re his only customer,” says George Monroy, Caine’s dad, in the film. “If you can get him one customer, that would make him happy.”

“At that point we hatched a plan to get everybody in L.A. to come play Caine’s Arcade,” Mr. Mullick says.

Mr. Mullick got on Facebook and organized a flashmob to come to the shop on a Sunday afternoon. The event information went viral and ended up on Reddit, which Mr. Mullick calls “the front page of the Internet.”

Caine’s dad agreed to take his son out for pizza to give the flashmob time to gather and construct colourful signs.

With a honest grin showing uneven teeth, Caine was clearly thrilled to see a massive crowd had gathered and were chanting “we came to play!”

“I saw they were cheering for me,” Caine says at the end of the video. “And I was proud.”

Mr. Mullick’s film has now been viewed nearly one million times on YouTube and 1.5 million times on Vimeo.

A fund set up to send Caine to university — where many have wondered if the boy will study engineering — quickly raised thousands of dollars.

An early push for fundraising for Caine came from Justin McElroy, a video game journalist and managing editor of the Polygon, a video game website that will go live later this year.